systemd-hwdb rebuilds /etc/udev/hwdb.bin from files in /var/lib/udev/hwdb.d/*
making a temp file first in /etc/udev/ then moving the tmp file
over hwdb.bin when complete. It also relabels based in file_contexts
This provides private type for /etc/udev/hwdb.bin
Signed-off-by: Dave Sugar <dsugar@tresys.com>